[PATCH newlib]New configuration option disable io vector buffer in Newlib

[Bin Cheng]

> -----Original Message-----
> From: newlib-owner@sourceware.org [mailto:newlib-owner@sourceware.org] On
> Behalf Of Corinna Vinschen
> Sent: Tuesday, March 26, 2013 8:31 PM
> To: newlib@sourceware.org
> Subject: Re: [PATCH newlib]New configuration option disable io vector buffer
> in Newlib
> 
> On Mar 26 18:13, Bin Cheng wrote:
> > Hi,
> > Stream IO functions in Newlib construct structures like __suio/__siov,
> > then call function __sfvwrite_r to do the buffered IO. From the view
> > of MCU programs, this layer code of vector buffer occupies large
> > amount flash and is generally unnecessary. So here this patch
> > introduces a new configuration time option
> > "--disable-newlib-fvwrite-in-streamio" allowing user to disable io
> > vector buffer in Newlib, thus reduces foot-print of stream-io and formatted
> IO.
> > The default behavior won't be changed unless the option "--disbale-*"
> > is specified explicitly when configuring.
> > I tested it with some formatted IO tests and also passed the gcc
> > regression test. It has also been applied in the release of "GNU Tools
> > for ARM Embedded Processors" and used in many projects I believe.
> >
> > Is it OK or any suggestions?
> 
> Your code looks pretty straightforward to me, so I don't see a reason not to
> apply it.  Except I don't understand your ChangeLog.  What's the non-existing
> _FSEEK_OPTIMIZATION having to do with it?  Typo?

Thanks for reviewing it. This is a typo, I have another patch for fseek optimization and I definitely mix them together.
Here is the right one:

2013-03-27  Bin Cheng  <bin.cheng@arm.com>
	* acconfig.h (_FVWRITE_IN_STREAMIO): Undef
	* newlib.hin (_FVWRITE_IN_STREAMIO): Undef
	* configure.in (--disable-newlib-fvwrite-in-streamio): New option.
	* configure: Regenerated.
	* libc/stdio/fputs.c (_fputs_r): Use _FVWRITE_IN_STREAMIO to
	control __sfvwrite_r.  Add alternative implementation.
	* libc/stdio/fputws.c (_fputws_r): Ditto.
	* libc/stdio/fwrite.c (_fwrite_r): Ditto.
	* libc/stdio/puts.c (_puts_r): Ditto.
	* libc/stdio/vfprintf.c (__ssputs_r, __sfputs_r): New function.
	(_VFPRINTF_R): Use _FVWRITE_IN_STREAMIO to control vector buffer.
	(__SPRINT): Use _FVWRITE_IN_STREAMIO to control macro definition.
	* libc/stdio/vfwprintf.c (_VFWPRINTF_R): Use _FVWRITE_IN_STREAMIO
	to control vector buffer.
	(__SPRINT): Use _FVWRITE_IN_STREAMIO to control macro definition.